In Zope 2 I used Folder Properties or tiny DTML items to plug bits of
text into Page Templates, typically items at the top or bottom of a page
that were inherited in subfolders until replaced.

In Zope 3 I guess I could use a method in a skin support class to
travers a folder tree until the required items are found, and I guess I
could use folder annotations to store the required items. Is this a
sensible approach? Or should I be subclassing IFolder to fiddle with
implicit acquisition?